Pset_GeoObsBoreholeGeophysicalInterval Properties for describing geophysical intervals. IfcGeoScienceObservation/BOREHOLELOG IfcGeoScienceObservation/BOREHOLELOG PwaveVelocity P-wave velocity of a rock or soil. SwaveVelocity S-wave velocity of a rock or soil. YoungModulus Elastic modulus, mean value, α=0°. PoissonRatio A measure of the lateral deformations in the elastic range. Poisson Ratio DryBulkDensity Ratio of the mass of the solid to the unit total volume (dry material). WetBulkDensity Ratio of the total mass to the unit total volume (material at its natural moisture content). Resistivity Electrical resistivity (Ohm-m). SpontaneousPotential Naturally occurring (static) electrical potential in the Earth. Spontaneous potentials (SP) are usually caused by charge separation in clay or other minerals, by the presence of a semipermeable interface impeding the diffusion of ions through the pore space of rocks, or by natural flow of a conducting fluid (salty water) through the rocks. Variations in SP can be measured in the field and in wellbores to determine variations of ionic concentration in pore fluids of rocks. GroundwaterTemperature Groundwater temperature observed at specific location or expected in the subject section. HoleDiameter Drilled Borehole diameter. Also referred to as "Caliper", continuous measurement of the as-drilled diameter inside the borehole. GammaRay Naturally occurring gamma radiation which characterizes the rock or sediment in a borehole or drill hole, measured by a gamma ray logging.